Vulnerability CVE-2026-2758: Information
Description
Use-after-free in the JavaScript: GC component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.
Severity: CRITICAL (9.8)
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Fixed packages
Package name | Branch | Fixed in version | Version from repository | Errata ID | Task # | State |
|---|---|---|---|---|---|---|
| firefox | sisyphus | 148.0-alt1 | 148.0-alt2 | ALT-PU-2026-3542-2 | 409187 | Fixed |
| firefox | sisyphus_loongarch64 | 148.0-alt0.port | 148.0-alt0.port | ALT-PU-2026-3960-1 | - | Fixed |
| firefox | p11 | 148.0-alt2 | 147.0.2-alt1 | ALT-PU-2026-4175-1 | 409232 | Testing |
| firefox-esr | sisyphus | 140.8.0-alt1 | 140.8.0-alt1 | ALT-PU-2026-3923-2 | 409748 | Fixed |
| thunderbird | sisyphus | 148.0-alt1 | 148.0-alt2 | ALT-PU-2026-3544-2 | 409185 | Fixed |
| thunderbird | sisyphus_riscv64 | 148.0-alt1 | 148.0-alt2 | ALT-PU-2026-3685-1 | - | Fixed |
| thunderbird | sisyphus_loongarch64 | 148.0-alt0.port | 148.0-alt0.port | ALT-PU-2026-4198-1 | - | Fixed |
References to Advisories, Solutions, and Tools
Hyperlink | Resource |
|---|---|
| https://bugzilla.mozilla.org/show_bug.cgi?id=2009608 |
|
| https://www.mozilla.org/security/advisories/mfsa2026-13/ |
|
| https://www.mozilla.org/security/advisories/mfsa2026-14/ |
|
| https://www.mozilla.org/security/advisories/mfsa2026-15/ |
|
| https://www.mozilla.org/security/advisories/mfsa2026-16/ |
|
| https://www.mozilla.org/security/advisories/mfsa2026-17/ |
|